Expansion of mortar bars in the presence of potassium acetate deicer

Carboxylate-based deicing and anti-icing chemicals became widely used in the mid 1990s, replacing more environmentally burdensome chemicals. Within a few years of their adoption, distress of portland cement concrete runways was reported by a few airports using the new chemicals. Distress manifested characteristics identical to that of alkali silica reactivity (ASR), but onset occurred early in the pavement’s operating life and with pavements thought to contain innocuous aggregate. The carboxylate-based deicing chemicals were suspected of exacerbating ASR-like expansion. Innocuous, moderately, and highly reactive aggregates were tested using modified ASTM C1260 and ASTM C1567 procedures with soak solutions containing deicer solutions and sodium hydroxide or potassium hydroxide. ASR-like expansion is exacerbated in the presence of potassium acetate. The expansion rate produced by a given aggregate is also a function of the alkali hydroxide used. Petrographic analyses were performed on thin sections prepared from mortar bars used in the experiments. Expansion occurred via two mechanisms; rupture of aggregate grains and expansion of paste

Conceptual Design of a Communication-Based Deep Space Navigation Network

As the need grows for increased autonomy and position knowledge accuracy to support missions beyond Earth orbit, engineers must push and develop more advanced navigation sensors and systems that operate independent of Earth-based analysis and processing. Several spacecraft are approaching this problem using inter-spacecraft radiometric tracking and onboard autonomous optical navigation methods. This paper proposes an alternative implementation to aid in spacecraft position fixing. The proposed method Network-Based Navigation technique takes advantage of the communication data being sent between spacecraft and between spacecraft and ground control to embed navigation information. The navigation system uses these packets to provide navigation estimates to an onboard navigation filter to augment traditional ground-based radiometric tracking techniques. As opposed to using digital signal measurements to capture inherent information of the transmitted signal itself, this method relies on the embedded navigation packet headers to calculate a navigation estimate. This method is heavily dependent on clock accuracy and the initial results show the promising performance of a notional system

A method for Cloud Mapping in the Field of View of the Infra-Red Camera during the EUSO-SPB1 flight

EUSO-SPB1 was released on April 24th, 2017, from the NASA balloon launch site in Wanaka (New Zealand) and landed on the South Pacific Ocean on May 7th. The data collected by the instruments onboard the balloon were analyzed to search UV pulse signatures of UHECR (Ultra High Energy Cosmic Rays) air showers. Indirect measurements of UHECRs can be affected by cloud presence during nighttime, therefore it is crucial to know the meteorological conditions during the observation period of the detector. During the flight, the onboard EUSO-SPB1 UCIRC camera (University of Chicago Infra-Red Camera), acquired images in the field of view of the UV telescope. The available nighttime and daytime images include information on meteorological conditions of the atmosphere observed in two infra-red bands. The presence of clouds has been investigated employing a method developed to provide a dense cloudiness map for each available infra-red image. The final masks are intended to give pixel cloudiness information at the IR-camera pixel resolution that is nearly 4-times higher than the one of the UV-camera. In this work, cloudiness maps are obtained by using an expert system based on the analysis of different low-level image features. Furthermore, an image enhancement step was needed to be applied as a preprocessing step to deal with uncalibrated data

Investigation of Deterioration of Joints in Concrete Pavements: Field Study of Penetrating Sealers

The objective of this research was to assess the efficacy of various waterproofing sealers applied to pavement joints with respect to limiting water ingress. The measure of water ingress was the chloride concentration profile as measured by scanning electron microscopy and energy dispersive spectroscopy. The fieldwork was conducted at the MnROAD facility. Cores were retrieved from pavements to assess the before condition. Various silane- and siloxane-based sealers were applied in 2013, and the pavements were exposed to service for two years. After two years, cores were retrieved. The chloride profiles for various pavement sites were compared before and after application of the sealer. No appreciable differences were noted. The lack of measured differences is attributed to the short time span allowed for ingress. The older pavements measured had a considerable degree of chloride ingress and, as such, small changes were difficult to detect. The newer pavement analyzed also showed no appreciable change, but it would be worth re-analyzing after more time has elapsed (e.g., two more years)

Beyond Safe Harbor: Risk of Exposing Location in De-Identified Clinical Data

The use of de-identified EHR data for clinical and translational research has increased significantly since the HIPAA Privacy Rule De-Identification standards went into effect -Inclusion of SDOH measures in de-identified research is increasing as well, which presents an inherent risk of re-identifying PHI (primarily location units smaller than the state) -Data warehouse architecture and institutional policies need to recognize the risk associated with providing multiple location-based indices -Research interests are secondary to privacy concerns throughout biomedical research, but particularly in de-identified research, which is intended to promote more secure access to EHR data while allowing for expedient access (fewer institutional barriers to entry)https://digitalcommons.unmc.edu/com_neuro_pres/1000/thumbnail.jp

Maintenance of ONC Terminology for i2b2 Metadata

ONC terminologies are constantly adding new content and deactivating existing codes. The University of Nebraska Medical Center (UNMC) deploys three primary code sets that require regular updating to support research: SNOMED CT, RXNORM / NDC, and LOINC. A problem across the i2b2 community is keeping these terminologies up-to-date and loading them into i2b2 for timely analysis of EHR data. We have developed tool kits for rapid deployment of SNOMED CT metadata and will be extending the work to RXNORM/NDC and LOINC.https://digitalcommons.unmc.edu/com_emerg_pres/1001/thumbnail.jp

Reversing the Trend of Large Scale and Centralization in Manufacturing: The Case of Distributed Manufacturing of Customizable 3-D-Printable Self-Adjustable Glasses

Although the trend in manufacturing has been towards centralization to leverage economies of scale, the recent rapid technical development of open-source 3-D printers enables low-cost distributed bespoke production. This paper explores the potential advantages of a distributed manufacturing model of high-value products by investigating the application of 3-D printing to self-refraction eyeglasses. A series of parametric 3-D printable designs is developed, fabricated and tested to overcome limitations identified with mass-manufactured self-correcting eyeglasses designed for the developing world\u27s poor. By utilizing 3-D printable self-adjustable glasses, communities not only gain access to far more diversity in product design, as the glasses can be customized for the individual, but 3-D printing also offers the potential for significant cost reductions. The results show that distributed manufacturing with open-source 3-D printing can empower developing world communities through the ability to print less expensive and customized self-adjusting eyeglasses. This offers the potential to displace both centrally manufactured conventional and self-adjusting glasses while completely eliminating the costs of the conventional optics correction experience, including those of highly-trained optometrists and ophthalmologists and their associated equipment. Although, this study only analyzed a single product, it is clear that other products would benefit from the same approach in isolated regions of the developing world

Reversing the Trend of Large Scale and Centralization in Manufacturing: The Case of Distributed Manufacturing of Customizable 3-D-Printable Self-Adjustable Glasses

Although the trend in manufacturing has been towards centralization to leverage economies of scale, the recent rapid technical development of open-source 3-D printers enables low-cost distributed bespoke production. This paper explores the potential advantages of a distributed manufacturing model of high-value products by investigating the application of 3-D printing to self-refraction eyeglasses. A series of parametric 3-D printable designs is developed, fabricated and tested to overcome limitations identified with mass-manufactured self-correcting eyeglasses designed for the developing world's poor. By utilizing 3-D printable self-adjustable glasses, communities not only gain access to far more diversity in product design, as the glasses can be customized for the individual, but 3-D printing also offers the potential for significant cost reductions. The results show that distributed manufacturing with open-source 3-D printing can empower developing world communities through the ability to print less expensive and customized self-adjusting eyeglasses. This offers the potential to displace both centrally manufactured conventional and self-adjusting glasses while completely eliminating the costs of the conventional optics correction experience, including those of highly-trained optometrists and ophthalmologists and their associated equipment. Although, this study only analyzed a single product, it is clear that other products would benefit from the same approach in isolated regions of the developing world

Free and open-source control software for 3-D motion and processing

RepRap 3-D printers and their derivatives using conventional firmware are limited by: 1) requiring technical knowledge, 2) poor resilience with unreliable hardware, and 3) poor integration in complicated systems. In this paper, a new control system called Franklin, for CNC machines in general and 3-D printers specifically, is presented that enables web-based three dimensional control of additive, subtractive and analytical tools from any Internet connected device. Franklin can be set up and controlled entirely from a web interface; it uses a custom protocol which allows it to continue printing when the connection is temporarily lost, and allows communication with scripts